Judge Robert Altham jailed Mr Blevins and Mr Roberts for 16 months and Mr Loizou for 15 months for their part in a protest in July 2017 near Cuadrilla’s shale gas site at Preston New Road near Blackpool.

This week it was revealed that Jane Watson, the sister of Judge Altham, had actively supported the shale gas industry in Lancashire and at the Preston New Road site.

Ms Watson is the managing director of a company that supplies the offshore oil and gas sector. She was named as a shale gas advocate by the North West Energy Task Force and she signed a letter to Lancashire County Council supporting Cuadrilla’s fracking proposals. DrillOrDrop report

The judicial code states:

“Where a close member of a judge’s family is politically active, the judge needs to bear in mind the possibility that, in some proceedings, that political activity might raise concerns about the judge’s own impartiality and detachment from the political process.”

Mr Marsden asked the Secretary of State for Justice:

“if he will undertake an investigation into compliance with the judicial code of conduct in relation to the trial at Preston Crown Court of Simon Blevins, Richard Roberts and Richard Loizou.”

He also asked whether Judge Altham had sought advice from the Ministry of Justice about the requirements of the code of conduct on his family connections.

In a third question, Mr Marsden asked the Secretary of State:

“If he will publish the guidance issued by his Department on the duty of care required of justices under the judicial code of conduct when presiding over a case where the circumstances involve industries in which the judge’s family members have a financial interest.”

The three campaigners were the first people to be sent to prison in the UK for taking part in protests against the shale gas industry.

The length of the sentences has been criticised as excessive by human rights campaigners, academics, environmentalists and politicians. More than 1,000 UK academics signed an open letter calling for a review of the jail term..

Last Saturday an estimated 500 people marched through the centre of Preston to the city’s jail where the three men are being held.

An appeal hearing against the sentences is scheduled for Wednesday 17 October 2018 in London.